Conventional image processing can use a level set and user information to segment an image, e.g., see U.S. Pat. No. 7,277,582, “User interactive level set methods for image segmentation.” The level set is evolved to minimize a cost function, wherein variances of image intensities object pixels and background pixels are used in cost function. The user can label pixels as object or background pixels and penalize deviations of the sign of the evolving level set from the sign of the user-labeled pixels, and nearby pixels with an isotropic weighting, i.e., the weighting is uniform in all directions.
However, conventionally, the user labels do not incorporate image intensity information. The variance terms in the level set evolution dominate and only pixels near user selected background locations remain as background.
FIG. 1 shows an image that has a failure of the segmentation with conventional user interaction. The correct segmentation shown in FIG. 2 is difficult to achieve.
It is an object of the invention to produce a segmentation that approximated the correct segmentation.